SCN5A Variant I1600M Detail

We estimate the penetrance of LQTS for SCN5A I1600M around 7% and the Brugada syndrome penetrance around 15%. SCN5A I1600M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1600M is not present in gnomAD. I1600M has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A I1600M around 7% (0/10) and the Brugada syndrome penetrance around 15% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.754 14 6
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance Density is our previously published method to calculate the average BrS/LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT3 BrS1 Other Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 14 0 1 - -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

I1600M has 43 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
1569 13 A1569P,
1586 12
1624 15 V1624I,
1568 10
1587 13 F1587V,
1602 6
1601 5 L1601H,
1609 14 S1609L, S1609W,
1575 9 C1575S,
1608 11
1600 0
1571 11 F1571C,
1572 9
1564 15
1570 15 I1570V, p.I1570dup, p.1570_F1571insI,
1599 4
1626 12 R1626H, R1626L, R1626P, R1626C,
1603 5 I1603F,
1625 10
1606 10 T1606I,
1576 12
1596 5 F1596I, F1596C,
1597 5 V1597M,
1573 13
1565 14 L1565M,
1594 12 F1594S,
1593 11 I1593M,
1595 10
1619 14 P1619Q, c.4856delC, P1619L,
1629 13 R1629X, R1629G, R1629Q,
1605 10 G1605C, G1605D, c.4813+3_4813+6dupGGGT, c.4813+2_4813+5dupTGGG, c.4813+5insTGGG,
1574 12 E1574K, c.4719C>T,
1616 12
1607 10
1592 13
1578 14 c.4732_4733dupAA,
1617 10 p.F1617del,
1604 7 V1604M, c.4810+3_4810+6dupGGGT,
1622 10
1618 13
1621 13
1579 12 L1579fsX53,
1598 6 V1598A,